Flu levels are soaring with one in five cases in hospital suffering fromthe deadly strain dubbed "Aussie flu", official figures show.

The statistics from Public Health England (PHE) show that across thecountry, rates of flu have close to doubled in one week, with a 51 percent rise in cases hospitalised.

The reports show almost 2,000 patients hospitalised with confirmed fluso far this season - with more than a fifth infected with the deadlystrain A(H3N2) - dubbed “Aussie flu” after it fuelled the country’sworst flu season for two decades.

The total death toll is now 85, up from 48 in previous reports this season.

Health officials have urged NHS staff to take up flu vaccinations, withthe country's chief medical officer today backing calls to make itmandatory for frontline staff to have the jabs.

Prof Dame Sally Davies pleaded with doctors and nurses to have the jabfor the sake of their patients, with less than one third of healthcarestaff vaccinated in some hospitals.

“Healthcare workers owe a duty to protect their patients – go and getvaccinated,” she said.

Pensioners, adults with chronic health problems like diabetes andasthma, pregnant women and children under the age of nine are alleligible for free NHS vaccination.

While 71 per cent of pensioners have been vaccinated, just 46 per centof pregnant women and 47 per cent adults in clinical risk groups havehad the jab, along with less than 50 per cent of children, the lateststatistics show.

The new figures show rates of GP consultations about flu have gone from21 per 100,000 people to 37.3 per 100,000 people in one week - a rise of78 per cent.

The Royal College of GPs said the figures meant almost 22,000 patientshad visited GPs with signs of flu in the first week of January - a riseof 9,499 patients since the last week of December.

Separate statistics suggest at least 4.5 million people in England aresuffering from flu.